I'm assuming the cell came first because in order for a virus to exist, it has to feed off the cell, but then when I looked on the internet, some people said the virus came first because of RNA, and RNA has existed way before DNA has.

The question is, in other words - which came first, host or parasite? Of course the host had to be here first, but that doesn't mean that non-parasitic species did not evolve earlier. Think about mammals and nematodes. Of course the nematodes evolved earlier than mammals. But the parasitic nematodes had to evolve after mammals.